Fata was arrested in August. He’s accused of committing fraud to enrich himself through health insurance programs. The government says his practice billed Medicare $225 million from August 2007 to July 2013. He could face trial this year.

An analysis by The Associated Press found that a tiny group, 344 out of more than 825,000 doctors, received $3 million or more apiece in 2012— a threshold that raises eyebrows for the government’s own investigators. Overall, about 2 percent of clinicians accounted for one-fourth of payments.